This invention relates generally to the commercial refrigeration art, and particularly to a refrigeration unit which, in use, is used to refrigerate a plurality of cooling zones.
A modular commercial refrigeration unit constructed and arranged for placement in strategic proximity to plural associated product cooling zones is known, and is disclosed in U.S. Pat. No. 5,440,894 commonly owned by HUSSMANN CORPORATION, the content of which is incorporated herein by reference. This prior art document discloses a supermarket or other food store refrigeration system including a refrigeration unit and a refrigeration network comprising a plurality of such units. The unit disclosed in U.S. Pat. No. 5,440,894 (marketed under the Trademark xe2x80x9cPROTOCOLxe2x80x9d) is intended for use in cooling the zones of plural fixtures within a shopping arena (including the food merchandising and display area and the food storage and preparation area) of a food store.
The refrigeration unit comprises a condensing unit rack configured to accommodate the maximum refrigeration loads of the associated zones and being constructed to support the components of a closed refrigeration circuit including a plurality of multiplexed compressor means and associated high side and low side refrigerant delivery and suction means extending from the rack and being operatively connected to evaporator means constructed and arranged for cooling the associates zones, and which unit also has condenser means with a cooling source remote from the compressor rack but operatively constructed and arranged to provide a heat exchange relationship for providing optimum condensing and efficiency of said evaporator means in cooling the associated zones.
Another modular commercial refrigeration unit constructed and arranged for strategic placement near plural associated product cooling zones is known, and is disclosed in U.S. Pat. No. 5,743,102, commonly owned by HUSSMANN CORPORATION, the content of which is incorporated by reference. This prior art document discloses food store refrigeration including a refrigeration unit and cooling system. The unit disclosed in U.S. Pat. No. 5,743,102 (marketed under the mark xe2x80x9cPROTOCHILLxe2x80x9d) is intended for cooling the product zones of plural display and storage merchandisers and fixtures. The unit comprises a condensing unit rack configured to accommodate the maximum refrigeration loads of associated fixture zones and being constructed to support components of a closed refrigeration circuit having multiplexed compressors and evaporator means with associated high side and low side refrigerant delivery and suction means operatively connected to the evaporator means, and which unit also includes condenser means operatively connected between the compressor and evaporator means as a component of the refrigeration circuit; and the unit also being constructed to support components of a coolant fluid system having heat transfer means associated with the evaporator means and pumping means for circulating a coolant through the heat transfer means in a closed coolant loop to cooling coils for the associated fixtures.
An important objective of the units disclosed in U.S. Pat. Nos. 5,440,894 and 5,743,102 was to seek to minimize the amount of refrigerant required in the food store refrigeration network.
A further object of the. units disclosed in U.S. Pat. Nos. 5,440,894 and 5,743,102 was to obviate the need for providing a dedicated remote plant/machine room thereby releasing valuable floor space within a supermarket or the like.
It has been found in practice that some merchants remain reluctant to position the prior art PROTOCOL and PROTOCHILL units anywhere on the sales floor of a store, thereby losing many of the refrigeration benefits which might be obtained.
It is an object of at least one aspect of the present invention to seek to address one or more of the perceived problems of the units disclosed in U.S. Pat. Nos. 5,440,894 and 5,743,102.
It is a further object of the present invention to provide a unit which, in use, effectively does not occupy any floor space.
It is yet a further object of at least one aspect of the present invention to seek to address the objects of the units as disclosed in U.S. Pat. Nos. 5,440,894 and 5,743,102.
Further objects and advantages of the unit of the present invention will become more apparent from the description provided hereafter.
Some of these various advantages provided by presently preferred embodiments of the present invention are:
low noise and vibration levels;
provision of two or more compressors so as to provide capacity control and back-up security;
relatively short coupled pipework thereby seeking to reduce capital and running costs and installation time;
relatively simple refrigeration circuitry;
reduced refrigerant charge and cost, as well as smaller refrigerant gas loss in an event of leakage;
flexibility for future retrofits;
heat reclaim from fluid loops providing an advantageous energy use and improved efficiency of the refrigeration system/network;
provision of a low profile for unobtrusive mounting on top of a cooling zone fixture.
According to a first aspect of the present invention there is provided a refrigeration unit adapted for cooling the multiple cooling zones such as a combination merchandiser or a plurality of fixtures, the unit including refrigeration circuit components comprising a close coupled compressor means, and wherein in use the unit is substantially contained within a footprint area similar to that of a cooling zone fixture.
Herein the term xe2x80x9cfootprintxe2x80x9d of a cooling zone is understood to mean the floor space area occupied by the refrigerated fixture as viewed from above (or below).
The unit may be used in a food store, such as a supermarket or the like.
A xe2x80x9ccooling zonexe2x80x9d may comprise the product cooling space or refer to the footprint taken by a merchandising, storage or processing cabinet or fixture.
One or more of such merchandising cabinets may be provided in-line, back to back, or in closely adjacent proximity.
The unit is preferably provided over or on top of one product cooling zone (fixture).
The compressor means preferably comprises two or more compressors that are multiplexed by being connected in parallel in the refrigeration circuits, and preferably the compressors are of a horizontal scroll type. This provides the advantage of a xe2x80x9clow-profilexe2x80x9d unit which may be providentially or strategically placed on top of one product fixture while being constructed and arranged to refrigerate the plural cooling zones of at least two closely associated fixtures. Such horizontal scroll compressors are available from HITACHI under model number FL 200DL, FL 300DL, FL 400DL and FL 500DL. Alternatively, one or more of the compressors may be of a vertical scroll type.
According to a preferred embodiment of the present invention, a modular low-profile refrigeration unit is configured to accommodate the maximum aggregate refrigeration loads of at least two product cooling zones provided in a food store area, the unit comprising closed refrigeration circuit components including a plurality of multiplexed compressor means and associated refrigerant high side delivery means and low side suction means, the unit being constructed and arranged for placement, in use, in strategic proximity to the product cooling zones, and being operatively connected to evaporator means for the respective zones, and the refrigeration circuit also including condenser means.
The condenser means may include a condenser within the unit, which in use may be operatively associated with a remote cooling source so as to provide a heat exchange relationship with the condenser.
The remote cooling source may be a fluid cooling source, such as a cooling tower or a ground source water supply, or a dedicated normal temperature refrigeration system, a chiller system or recirculating water source or a combination of such alternate fluid cooling sources to assure the condenser means of a continuous supply of liquid coolant at a substantially constant temperature.
Alternatively, the condenser means may comprise a condenser remote from the unit and having a heat exchange cooling source, such as being air cooled.
Whether the condenser is located on board the refrigeration unit per se or remote therefrom, the condensing means may include heat reclaim which may be direct or as a heat pump.
According to a second aspect of the present invention there is provided a refrigeration system which includes at least one refrigeration unit according to the first aspect of the present invention.
The refrigeration unit of the system will cool the cooling zones of at least two fixtures, and the unit is substantially contained within the footprint size of one of the fixtures.
According to a preferred form of the second aspect of the invention, the system comprises a modular food store refrigeration system comprising: a plurality of cooling zones for at least two refrigerated fixtures having first closely adjacent locations in the store, separate (discrete) first stage evaporator means for cooling the refrigerated fixtures to maintain food product temperatures therein, the compressor means comprising multiplexed scroll type first stage compressors having a second location in the store in closely adjacent proximity to the first locations of the refrigerated fixtures, and first stage condenser means connected together with said first stage compressors and said first stage evaporator means to form a first stage closed loop refrigeration circuit; an exterior heat exchanger and a closed liquid heat transfer loop extending between the first stage refrigeration circuit and the exterior heat exchanger to transfer heat from the first stage condenser means to the exterior heat exchanger.
According to a third aspect of the present invention there is provided a refrigeration network including at least one refrigeration unit according to the first aspect of the present invention.
According to a preferred form of the third aspect of the present invention the network comprises:
a first modular refrigeration system unit according to the second aspect of the invention is placed in close strategic proximity to first cooling zones and includes first closed refrigeration circuit components including plural multiplexed compressor means with high side receiver means and associated high side and low side refrigerant delivery and suction means operatively connecting first evaporator means for cooling said first refrigerated zones, and said first refrigeration unit also including first condenser means operatively connected in the high side downstream of the compressor means;
at least one other modular refrigeration system unit placed in close strategic proximity to associated other cooling zones and comprising other closed refrigeration circuit components including other plural multiplexed compressor means with associated high side and low side refrigerant delivery and suction means operatively connecting other evaporator means for cooling the other refrigerated zones, and said other refrigeration unit also including other condenser means operatively connected in the high side downstream of the other compressor means;
and wherein the network may include the respective condensing means and a coolant circulating system having a plurality of heat exchanger circuits in heat exchange relationship with the respective first and other condensing means for the respective first and other refrigeration system units, said coolant circulating system having at least one continuous cooling source for the coolant in said circulating system.
According to a fourth aspect of the present invention there is provided a method of commercially refrigerating a plurality of cooling zones comprising: providing each cooling zone with at least one cooling coil; providing a refrigeration unit adapted for cooling the plurality of cooling zones; and locating the unit on top of the fixture for at least one of the cooling zones so as to be substantially contained within a footprint area of the selected one cooling zone.
According to a second embodiment of the invention, a modular commercial refrigeration unit configured to accommodate the aggregate refrigeration loads of at least two fixture cooling zones comprises a rack mounted closed circuit vapor phase refrigeration system having plural compressor means and an evaporative heat exchange means, and coolant fluid circulating means having a closed coolant loop in heat exchange relation with said evaporative heat exchanger and with coolant heat exchanger means for the cooling zones.
According to another aspect of the present invention, the refrigeration system and unit of the second embodiment is constructed and arranged for mounting within the footprint size of one cooling zone fixture. In this aspect, the unit may employ horizontally disposed scroll compressors and be disposed horizontally on top of a selected fixture, especially if the fixture is free standing in the shopping area of a food store.
Alternatively, the unit may employ vertical scroll compressors and be vertically disposed on top of a selected product fixture, especially if the fixture is positioned against a vertical store wall.